#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<cstring>
#include<algorithm>
#include<cstdlib>
#include<cstdio>
#include<queue>
using namespace std;
typedef long long LL;
const int maxn = 3000006;
int n,c = 1,t[maxn][26];
int cnt[maxn];
void insert(char s1[]){
    int u = 0,m = strlen(s1);
    for (int i = 0; i < m; i++){
        int ch = s1[i] - 'a';
        if (!t[u][ch] || !cnt[t[u][ch]]) t[u][ch] = c++;
        u = t[u][ch];
        cnt[u]++;
    }
}
void del(char s1[]){
    queue<int> Q;
    int u = 0;
    int m = strlen(s1);
    for (int i = 0; i < m - 1 ; i++){
        int ch = s1[i] - 'a';
        if (!cnt[t[u][ch]]) t[u][ch] = 0;
        if (!t[u][ch]) return;
        u = t[u][ch];
        Q.push(u);
    }
    int x = cnt[t[u][s1[m - 1] - 'a']];
    t[u][s1[m-1] - 'a'] = 0;
    while (!Q.empty()){
        u = Q.front();
        Q.pop();
        cnt[u]-=x;
    }
}
bool search(char s1[]){
    int u = 0;
    int m = strlen(s1);
    for (int i = 0; i < m - 1; i++){
        int ch = s1[i] - 'a';
        if (cnt[t[u][ch]] == 0) t[u][ch] = 0;
        if (!t[u][ch]) return 0;
        u = t[u][ch];
    }
    return cnt[t[u][s1[m - 1] - 'a']];
}
int main(){
    scanf("%d", &n);
    char s[100],s2[100];
    for (int i = 0; i < n; i++){
        scanf("%s%s", s, s2);
        if (strcmp(s, "insert") == 0){
            insert(s2);
        }
        else if (strcmp(s, "delete") == 0){
            del(s2);
        }
        else {
            if (search(s2)) printf("Yes\n");
            else printf("No\n");
        }
    }
    return 0;
}